1. Field of the Invention
The present invention generally relates to a liquid crystal module. More specifically, the present invention relates to a liquid crystal module having a light reflecting sheet.
2. Background Information
A conventional direct backlight type of liquid crystal module has a frame, a light reflecting sheet, a cold cathode tube, an optical sheet, a liquid crystal panel and a bezel. The light reflecting sheet is provided in an interior of the frame. The cold cathode tube, the optical sheet and the liquid crystal panel are disposed above the light reflecting sheet. The bezel is installed from above to hold down a peripheral edge of the liquid crystal panel. With the liquid crystal module, a plurality of protrusions is formed on edge frame parts of the frame. The light reflecting sheet is positioned by fitting the protrusions into holes formed in end edge parts of the light reflecting sheet.
With another conventional liquid crystal module, a first prong part protruding from one short side of an optical sheet is fixed to a frame. A second prong part protruding from the other short side is fitted into a recess in the frame. A positioning protrusion formed on a bottom face of the recess is inserted in a slot formed in the second prong part. This allows relative displacement between the frame and the second prong part (see Japanese Laid-Open Patent Application Publication No. 2001-91947, for example).
With a conventional lighting device for a liquid crystal display device, a cut-out is provided to a side face of a frame that houses a light guide plate, a light source, a light reflector, a light diffusing plate, etc. A convex component is provided to a light diffusing plate or a prism sheet. The convex component is aligned merely by latching the convex component to the cut-out (see Japanese Laid-Open Patent Application Publication No. 2000-340017, for example).
With a conventional backlight device, fitting holes for positioning and supporting optical sheets are formed in side walls of a housing. Fitting convex components are provided to at least the optical sheets adjacent to the housing. The optical sheets are thereby positioned and supported (see Japanese Laid-Open Patent Application Publication No. 2000-19512, for example).
However, with the conventional liquid crystal modules, there is a limit to the height of the protrusions formed on the edge frame parts of the frame, and the protrusions can not be formed very tall. Thus, the protrusions readily come out of the holes in the light reflecting sheet. As a result, the light reflecting sheet becomes misaligned. Consequently, when the protrusions are fitted into the holes, double-sided tape or the like is used to affix the end edge parts of the light reflecting sheet to the edge frame parts of the frame so that the protrusions do not come out of the holes. This affixing entails extra work as well as the cost of the tape. Thus, assembly work becomes less efficient and the manufacturing cost becomes higher.
With the liquid crystal module of Japanese Laid-Open Patent Application Publication No. 2001-91947, the second prong part of the optical sheet is prone to coming out of the recess in the frame. With the lighting device of Japanese Laid-Open Patent Application Publication No. 2000-340017, the convex component of the light diffusing plate, etc., is prone to coming out of the cut-out in the frame. Thus, the above-mentioned problems are difficult to solve even when the positioning means are employed.
In contrast, with the backlight device of Japanese Laid-Open Patent Application Publication No. 2000-19512, because the optical sheets are positioned and supported by fitting the fitting convex components of the optical sheets from an inside into the fitting holes in the side walls of the housing, the optical sheets do not readily come out. However, with a means such as this for positioning and supporting optical sheets, because the fitting convex components readily come out of the fitting holes when the optical sheets are flexed or bent. Thus, this is unsuitable for positioning and supporting light reflecting sheet bent into a concave shape.
In view of the above, it will be apparent to those skilled in the art from this disclosure that there exists a need for an improved liquid crystal module. This invention addresses this need in the art as well as other needs, which will become apparent to those skilled in the art from this disclosure.